[ntp:questions] Re: simple time server

Serge Bets serge.bets at NOSPAM.laposte.invalid
Fri Aug 4 13:58:35 UTC 2006


Hi Bryan,

 On Thursday, August 3, 2006 at 18:10:38 +0000, Bryan Henderson wrote:

> I use Hwclock and its adjtime file to take care of hardware clock
> drift while the kernel is not running, but that works only if Hwclock
> is the only thing that ever sets the hardware clock.

That's a good reason to want to disable the RTC update every 11 minutes.
I heard that some kernels have a setting to disable it. Most don't, but
can be trivially patched. Removing any code setting the RTC, you can
safely have STA_UNSYNC cleared by ntpd, without eleven minutes mode. It
works very well: I also prefer to rely exclusively on hwclock drift
correction, and do so.

Note that the temperature of the RTC chip, and thus its drift rate, may
not be exactly the same when the kernel runs, and during some forms of
"doesn't run". The difference can be huge, around 1s/day.

Thank you for hwclock, Bryan. :-)


Serge.
-- 
Serge point Bets arobase laposte point net




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